There are many possible reasons for Mandevilla leaves curling, from overwatering and underwatering to other problems like low sunlight.
In this guide, we’ll look at the seven most common reasons for this and what you can do in each case to get your plant back to health.
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7 Causes For Mandevilla Leaves Curling
Mandevilla leaves curling is a sign that your plant is unhappy.
If you are experiencing this problem, start by looking through the seven reasons below to determine why it is happening.
1. Overwatering
Overwatering is a common cause of Mandevilla leaves curling.
Overwatered leaves will curl up and turn yellow, which makes them very obvious to identify.
When you water your plant too frequently, the roots can become waterlogged, leading to root rot. This happens for one of two reasons – either the roots suffocate and rot as they die, or dormant fungi in the soil becomes active in overwatered conditions, which causes the roots to rot.
Overwatering can also happen if there is a period of heavy rainfall, so it’s essential to use well-draining soil to help prevent this.
2. Underwatering
Underwatering can also lead to curling leaves, but in this case, the leaves turn brown and crispy to the touch as they curl up.
This happens as the plant tries to maintain moisture during periods of droughts. The leaves lose moisture as a result and turn brown in the process.
3. Improper Sunlight Exposure
Mandevilla plants need lots of bright, indirect sunlight to thrive. Depending on temperature and humidity, some can also grow well in full light.
If there isn’t enough sunlight, the plant will suffer, and the leaves will curl. Other symptoms, like a lack of overall growth and blooming, will also become more apparent.
4. Wrong Type Of Soil
Mandevilla plants prefer well-draining soil that is rich in organic matter.
If the soil is too heavy or compacted, it can lead to poor drainage and root rot. On the other hand, soil that drains too quickly can lead to underwatering, so it’s important to find the right balance.
5. Temperature Fluctuations
Mandevilla plants are tropical plants that thrive in warm temperatures.
The leaves may curl to protect themselves from the cold if the temperature drops too low. To protect it, You should keep your Mandevilla inside when the temperature drops below 50 degrees Fahrenheit.
6. Nutrient Deficiencies/Overfertilizing
Nutrient deficiencies and overfertilizing (also called fertilizer burn) can cause the leaves on Mandevillas to curl.
Certain nutrients like nitrogen are responsible mainly for leaf development, while others like phosphorus are crucial for root development and blooming.
If these nutrients are lacking, either through a low-quality soil mix or not adding fertilizer to the soil, the leaves can suffer and curl.
Overfertilizing can also be an issue, however, as excess salts in the soil can burn the roots, which can cause similar symptoms to root rot and also cause the leaves to curl.
7. Pests And Diseases
Mandevilla plants can be susceptible to various pests, including aphids, spider mites, whiteflies, and scales.
These types of pests feed on the sap found within the leaves, causing damage to the leaves and leaving behind a honeydew residue. This can also result in sooty mold growth, spreading quickly between leaves.
Mandevillas can also be susceptible to diseases like Botrytis blight and leaf spots, which affect the leaves and cause them to curl and die.
How To Prevent Mandevilla Leaves Curling
It’s much easier to prevent the leaves from curling in the first place, so here are some easy tips you can implement to make this happen.
Remember that some leaves will die every so often and curl as they do – we’re only talking about when multiple leaves start to curl here.
Proper Watering Techniques
Improper watering is one of the main reasons for Mandevilla leaves curling.
To water properly, check the soil every time before you water. If the top couple of inches are dry, water the soil; it’s that simple.
Overwatering can have more severe consequences than underwatering, so if you are unsure, it’s better to water your Mandevilla less than often.
Optimal Light And Temperature Conditions
Mandevilla plants require bright, indirect sunlight to thrive.
Too much direct sunlight can cause the leaves to curl and burn, while too little light can cause the plant to become leggy and weak.
Mandevillas prefer warm temperatures, ideally between 70°F and 80°F. It’s also ideal if you can keep the temperature fairly constant and avoid large temperature fluctuations.
Nutrient Management
Proper nutrient management is essential for Mandevilla plants.
Fertilize your plant every two weeks during the growing season with a balanced fertilizer to ensure it gets the necessary nutrients.
However, be careful not to over-fertilize, as this can lead to salt build-up in the soil and cause root damage.
Disease And Pest Control
The vast majority of diseases are caused by excessive moisture, either in the soil or on the leaves.
Avoid misting your Mandevilla, and make sure it has good air circulation around the leaves to help excess moisture evaporate. Use well-draining soil as before, and don’t overwater the soil.
Pests are also attracted to moisture, so many of the same rules apply. With pests and diseases, checking the leaves for symptoms regularly and acting quickly before they spread is important.
When To Repot And Prune Mandevilla
It’s important to know when to repot and prune your Mandevilla, and curling leaves can indicate that this is what you need to do.
Here’s my advice:
If You’re Unsure What To Do
If you’re worried about your Mandevilla, checking the roots is a good idea.
This way, you’ll know whether the roots are damaged, and you can take things from there. To do this, gently dig around the root ball and pull it out of the soil from the center.
Examine the roots for any signs of rot – affected roots will be discolored, mushy, and emit a foul odor.
If the roots are white and healthy, this can be ruled out as an issue. You should also check the soil and make sure it is moist but not too dry or saturated with water.
Ideal Mandevilla soil should be packed with organic material and sand to boost drainage.
If The Leaves Are Brown, Crispy And The Soil Is Dry
Pulling up the root ball is unnecessary in this case, as the plant must be watered thoroughly.
It’s a good idea to move your Mandevilla into a more shaded location to reduce further moisture loss, and then all that’s left to do is water the soil generously.
Wait for water to come out of the drainage holes and let the plant recover for a week or two. Prune any dead leaves, and move it back to it’s original location when the new leaves start to look healthy.
If The Leaves Are Yellow And Curling
If the leaves curl and turn yellow, it’s a pretty strong indication of overwatering.
If there is water visible on the top of the soil, then this pretty much confirms overwatering. Remove the root ball as before and trim any rotten roots using a sterilized pruning tool.
Treat the remaining roots with a fungicide and repot in a completely fresh soil mix that drains well. Water the soil lightly, prune affected leaves, and monitor it over the next few weeks.
In Summary
Mandevilla leaves curling is a lot more common of a problem than you would expect.
Hopefully, this guide has given you the information you need to figure out exactly what is wrong with your Mandevilla and how to fix it.
Check out some of our other Mandevilla articles below:
